System and method for balancing a centrifuge rotor

Abstract

To provide an improved system and method for balancing a centrifuge rotor.SOLUTION: A hub assembly 10 for a centrifuge rotor 12 includes a rotor hub 14 including a head portion 20, an elongated shaft portion 22 extending axially away from the head portion 20, and a central bore 102 extending through the head and shaft portions 20, 22. A system and method for balancing a centrifuge rotor 12 in which a head 20 includes a plurality of balance holes 52 each configured to selectively receive at least one balance weight 16 for balancing the centrifuge rotor 12.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates generally to centrifuge rotors, and more particularly to balancing rotors for use with centrifuges. [Background technology]

[0002] Centrifuge rotors are typically used in laboratory centrifuges to hold samples during centrifugation. While centrifuge rotors can vary significantly in construction and size, one common rotor structure is the fixed-angle rotor, which has a solid rotor body with multiple cell hole cavities radially distributed within the rotor body and arranged symmetrically about the axis of rotation. Samples are positioned within the cavities, allowing multiple samples to be centrifuged.

[0003] Centrifuge rotors must be carefully balanced because they are typically used in high-speed applications where centrifuge speeds can exceed hundreds or even thousands of revolutions per minute. In this regard, variations in the mass of the rotor load can cause undesirable force imbalances at high rotor speeds. This force imbalance can distort the spindle that drives the rotor, causing damage to the centrifuge, as well as reduced efficiency, wear, and noise. Traditional balancing techniques use a combination of samples and balance tubes, all of equal weight, or various other balancing patterns that do not use balance tubes.

[0004] A diagnostic device or balancing machine, such as those commercially available from American Hofmann Corporation of Lynchburg, Virginia, or Schenck Corporation of Deer Park, New York, can be used to detect rotor imbalance and identify specific locations on the rotor body where additional weights are needed to properly balance the rotor. Holes are then manually drilled at the identified locations in the rotor body, which may be constructed of carbon fiber, and weights are press-fit into these holes according to information provided by the diagnostic device. The weights can be, for example, metal cylinders with a specific mass to counteract the imbalance detected by the diagnostic device.

[0005] Rotors often need to be rebalanced multiple times over their lifespan. For example, as a rotor ages and wears, its mass distribution may change, thereby requiring rotor rebalancing. When this occurs, previously installed weights typically must be removed from previously drilled holes, new holes must be drilled in the rotor body, and the same or new weights may be press-fit into these new holes. The previously drilled holes are therefore rendered unused. It is often desirable to seal the previously drilled holes for structural and / or aesthetic purposes, which requires repair of the rotor body. The cycle of drilling new holes in the rotor body and repairing the rotor body to seal the previously drilled holes is repeated each time the rotor is rebalanced.

[0006] Therefore, it would be desirable to provide an improved system and method for balancing centrifuge rotors that addresses these and other problems associated with conventional rotors. Summary of the Invention

[0007] The present invention overcomes these and other shortcomings and drawbacks of currently known systems and methods for balancing centrifuge rotors. While the present invention will be discussed in connection with specific embodiments, it will be understood that the invention is not limited to these embodiments. On the contrary, the invention includes all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention.

[0008] According to one embodiment, a rotor hub assembly for a centrifuge rotor is provided, the rotor hub assembly having a rotor hub including a head, an elongated shaft portion extending axially away from the head, and a central bore extending through the head and the shaft portion, the head including a plurality of balance bores each configured to selectively receive at least one balance weight.

[0009] To balance the rotor, a diagnostic device may be used to detect imbalances in the rotor and identify at least one target location on the rotor hub and at least one corresponding target weight amount, which can be added to the hub at the target location to aid in proper balancing of the rotor. A suitable balance hole corresponding to the target location and a balance weight having a weight relatively close to the target weight amount may then be selected.

[0010] In one embodiment, the at least one balance weight includes at least one set screw having at least one threaded outer surface, and the plurality of balance holes are threaded.

[0011] The head of the rotor hub may include a plurality of fastening holes, each configured to selectively receive a fastener for attaching the at least one ring to the rotor hub. In one embodiment, the at least one ring is attached to the rotor hub and covers at least one balance weight inserted into the at least one balance hole. The ring may include at least one of a magnetic ring or an annular shield. If the ring is magnetic, the magnetic ring may include a plurality of blind holes on its upper surface for selectively receiving a plurality of corresponding magnets. Selective arrangement of the magnets on the magnetic ring produces an identifiable magnetic field via the Hall effect that may be detectable by the centrifuge or its associated sensor / reader, thereby allowing the centrifuge to identify the rotor hub and / or rotor installed therein. When the ring is a shield, the shield may be constructed of a highly magnetic material that can prevent the magnetic field produced by the magnets from being directed upward toward the hub, but rather concentrate the magnetic field downward toward the centrifuge's sensor / reader.

[0012] According to another embodiment, a centrifuge rotor is provided, the centrifuge rotor including a rotor body having a plurality of tubular cavities, each cavity configured to receive a sample container therein, the centrifuge rotor further including a rotor hub assembly as described above, the rotor hub configured to transmit torque from a centrifuge spindle to the rotor body.

[0013] A method for operating a centrifuge rotor is also provided, the rotor rotor including a rotor body having a plurality of tubular cavities and a rotor hub having a plurality of balance holes, each configured to selectively receive at least one of a plurality of balance weights.

[0014] In one embodiment, a method includes detecting an imbalance in a centrifuge rotor and selectively engaging at least one of a plurality of balance weights with at least one of a plurality of balance holes in response to the detected imbalance.

[0015] The balancing method may also include identifying at least one target location on the rotor hub and at least one corresponding target amount of weight to add to at least one target location below the hub to balance the rotor.

[0016] The exemplary method may also include selecting at least one of the plurality of balance holes and at least one of the plurality of balance weights in response to the at least one identified target location and the at least one corresponding target weight amount, respectively.

[0017] Various additional features and advantages of the present invention will become more apparent to those skilled in the art upon review of the following detailed description of the illustrative embodiments, when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the general description of the invention presented above and the detailed description presented below, serve to explain the invention.

[0019] [Figure 1] FIG. 1 is a perspective view of a hub assembly for a centrifuge rotor according to one embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the hub assembly of FIG. 1. [Figure 3A] 3A is an exploded cross-sectional view of the hub assembly of FIG. 1 taken along section line 3A-3A. [Figure 3B] 3B is an exploded cross-sectional view of the hub assembly of FIG. 1 taken along section line 3B-3B. [Figure 4] 2 is a cross-sectional view of a centrifuge rotor including the hub assembly of FIG. 1. [Figure 5] FIG. 5 is a cross-sectional view similar to FIG. 4 of a centrifuge rotor and hub assembly according to an alternative embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1-3B, an exemplary hub assembly 10 for a centrifuge rotor 12 (FIG. 4) is illustrated in accordance with one embodiment of the present invention. Hub assembly 10 includes a rotor hub 14 and at least one balance weight 16 removably mountable within rotor hub 14. As described in more detail below, balance weight 16 may be selectively positioned at various predetermined locations on rotor hub 14 to balance rotor 12.

[0021] The illustrated rotor hub 14 may be constructed of a metallic material, such as titanium, and includes a head 20 and an elongated shaft portion 22 extending axially from the head 20. The shaft portion 22 includes a threaded outer end surface 24 distal to the head 20 and a threaded outer mid-surface 26 proximal to the head 20. As best shown in Figures 3A and 3B, a central multi-step bore 30 extends through the head 20 and shaft portion 22 of the rotor hub 14 and includes a threaded inner surface 32 located within the shaft portion 22 distal from the head 20.

[0022] The rotor hub 14 includes an annular recess 34 on its bottom side distal from the shaft portion 22, with a plurality of circumferentially spaced threaded fastener holes 36 opening into the recess 34. Each of the fastener holes 36 is configured to threadably receive a corresponding fastener 38 for attaching a ring, such as a magnet ring 40 and / or annular shield 42, to the bottom side of the rotor hub 14. In this regard, the illustrated magnet ring 40 includes a plurality of through holes 44, each configured to receive a corresponding one of the fasteners 38. The magnet ring 40 may also include a plurality of blind holes 46 on its top side for selectively receiving a plurality of corresponding magnets 48. The selected arrangement of the magnets 48 on the magnet ring 40 produces a magnetic field identifiable via the Hall effect that may be detectable by the centrifuge (or a sensor / reader associated therewith), thereby enabling the centrifuge (or a controller associated therewith) to identify the hub 14 and / or rotor 12, as will be understood by those skilled in the art. For example, the centrifuge (or its controller) may compare the detected magnetic field to various magnetic field values ​​stored in a database to identify the particular rotor 12 or type of rotor 12 within the centrifuge.

[0023] The illustrated annular shield 42 includes a plurality of through holes 50 each configured to receive a corresponding one of the fasteners 38, such that the annular shield 42 may be sandwiched within the recess 34 between the magnet ring 40 and the head 20 of the rotor hub 14 when the fastener 38 is threadably received in the corresponding fastener hole 36. The shield 42 may be constructed of a highly magnetic material capable of preventing the magnetic field produced by the magnets 48 from being directed upward toward the hub 14, and instead concentrating the magnetic field downward toward the centrifuge's sensors / readers. In one embodiment, the shield 42 may be constructed of mu-metal (e.g., ASTM A753 Alloy 4).

[0024] The exemplary head 20 of the rotor hub 14 further includes a plurality of circumferentially spaced, threaded balance holes 52 that open to the recess 34. In the embodiment shown, each of the balance holes 52 extends generally parallel to the central bore 30 of the rotor hub 14. Each of the balance holes 52 is configured to selectively and threadably receive one of the balance weights 16 for balancing the rotor 12. More particularly, the balance holes 52 may have a uniform configuration, such that each of the balance holes 52 has the same depth, cross-sectional dimension, and / or thread pitch, for example. In this manner, each of the balance holes 52 may be capable of threadably receiving the same balance weight 16. In the embodiment shown, the uniform configuration of the balance holes 52 differs from the configuration of the fastener holes 36, such that the balance holes 52 may be exclusively adapted to receive balance weights 16, while the fastener holes 36 may be exclusively adapted to receive fasteners 38.

[0025] In the illustrated embodiment, eight balance holes 52 are provided, spaced apart circumferentially about the central hole 30 in four pairs, as best shown in FIG. 2 . The balance holes 52 therefore define eight predetermined locations on the rotor hub 14 for receiving the balance weights 16. However, any suitable number of balance holes 52 may be used at any suitable spacing. In this regard, the cross-sectional dimensions of the head 20 may affect the surface area available for the balance holes 52; for example, the cross-sectional dimensions may be increased to provide additional surface area to accommodate a greater number of balance holes 52. It will be appreciated that the number of balance holes 52 may correlate to the number of options for positioning the balance weights 16 and may also correlate to the degree of control of the center of gravity of the rotor hub 14, which affects the stability of the rotor 12.

[0026] The illustrated balance weight 16 includes a set screw 60 having a threaded exterior surface 62 and extending between a first end 64 and a second end 66 that define the length of the balance weight 16. The first end 64 is provided with a hex socket 68 for receiving a tool, such as a wrench, to assist in advancing the balance weight 16 into or out of one of the balance holes 52. The threaded exterior surface 62 of the balance weight 16 allows the balance weight 16 to be easily inserted into or removed from one of the balance holes 52 without causing any deformation to the rotor hub 14 or any other component of the rotor 12. While the illustrated balance weight 16 and balance holes 52 are threaded so that the balance weight 16 can be reliably and removably engaged with one or more of the balance holes 52, the balance weight 16 can be reliably and / or removably engaged with the hub 14 by any other suitable means. In one embodiment, multiple balance weights 16 having a variety of different lengths and / or masses can be provided so that balance weights 16 having different balancing characteristics can be selectively positioned within particular balance holes 52 to achieve customized balancing.

[0027] In the embodiment shown, the balance weight 16 may be covered by the magnet ring 40 and / or the annular shield 42 or may be concealed within the corresponding balance hole 52 by the magnet ring 40 and / or the annular shield 42 so that the balance weight 16 is not visible or easily accessible from outside the hub assembly 10.

[0028] 4, rotor hub assembly 10 may be used in a centrifuge rotor 12. Rotor 12 includes a rotor body 70 that is symmetrical about an axis of rotation defined by rotor hub 14, about which a sample contained in a sample container (not shown) positioned within rotor body 70 may be centrifugally spun.

[0029] The illustrated rotor body 70 includes a generally cylindrical bore 72 for receiving at least the shaft portion 22 of the hub 14, and the bore 72 is configured to be coaxial with the hub 14, such that the bore 72 also defines an axis of rotation. As shown, the periphery of the bore 72 is provided with a plurality of recesses 74, the purpose of which will be explained below. The rotor body 70 also includes an upper cavity 76 and a lower cavity 78 adjacent opposite ends of the bore 72.

[0030] A plurality of tubular cell hole cavities 80 extend from the upper cavity 76 into the rotor body 70. Each of the cavities 80 is suitably sized and shaped to receive at least one of the sample containers therein for centrifugal rotation of the containers about the axis of rotation. It will be appreciated that any suitable number of cell hole cavities 80 may be used. As used herein, the term "tubular" refers to any suitable cross-sectional shape, including, but not limited to, rounded corners (e.g., elliptical, circular, or conical), quadrilateral, regular polygon, or irregular polygon, or any other suitable shape. Thus, the term is not intended to be limited to the generally circular cross-sectional profile of the exemplary cavity 80 illustrated in the figures. In one embodiment, the rotor body 70 is constructed of carbon fiber material. For example, the rotor body 70 may be compression molded from layers of resin-coated carbon fiber laminate material.

[0031] In the embodiment shown, the rotor body 70 and a rotor insert 82 are co-molded within the bore 72. The insert 82 includes at least a threaded bore 84 for receiving and threadingly engaging the threaded outer interface surface 26 of the shaft portion 22 of the hub 14 to securely mount the rotor body 70 on the hub 14. The insert 82 also includes a plurality of webs 86 that are each received within a corresponding one of the recesses 74 of the rotor body 70. In use, as the rotor 12 is turned, the hub 14 applies a torque to the insert 82, which in turn applies a torque to the rotor body 70, e.g., via engagement between the webs 86 and the recesses 74.

[0032] With rotor body 70 resting on rotor hub 14, hub retainer 90 is removably fastened to hub 14 to further facilitate holding rotor body 70, hub 14, and insert 82 in position relative to one another. In this regard, hub retainer 90 includes at least a threaded bore 92 for receiving and threadingly engaging threaded outer end surface 24 of shaft portion 22 of hub 14.

[0033] The rotor 12 also includes a lid 100 that is removably coupled to the rotor hub 14 over the rotor body 70, for example, to aid in retaining sample vessels therein during rotation of the rotor body 70. The illustrated lid 100 is generally disk-shaped and includes a central hole 102, the purpose of which will be explained below, and a peripheral groove 104 for receiving an O-ring 106 to provide a fluid-tight seal between the lid 100 and the rotor body 70 when the lid 100 is removably coupled to the rotor body 70. In one embodiment, the lid 100 is constructed of a carbon fiber material. For example, the lid 100 may be compression molded from layers of a resin-coated carbon fiber laminate material.

[0034] As shown, the lid 100 can be removably coupled to the rotor body 70 via a lid screw 110. The illustrated lid screw includes an upper flange 112, a threaded lower outer surface 114, and a multi-step bore 116. As shown, the threaded lower outer surface 114 is received by and threadingly engages the threaded inner surface 32 of the hub 14, causing the upper flange 112 to press a spacer 118 against the lid 100. When the lid 100 is removably coupled to the rotor body 70 via the engagement of the lid screw 110 with the hub 14 and the spacer 118 with the lid 100, it prevents access to sample vessels held within the cavities 80, such as during high-speed rotation. A tie-down screw or pin 120 can be inserted through the bore 116 of the lid screw 110 and threadingly coupled to a knob 122. The tie-down pin 120 may be configured to engage with a cooperating bore in a centrifuge spindle (not shown), which thus aids in attaching the rotor 12 to the centrifuge spindle. As shown, the tie-down pin 120 may be biased away from the centrifuge spindle by a helical spring 124. A threshold force of the helical spring 124 may be overcome, urging the tie-down pin 120 into engagement with the bore in the centrifuge spindle, which may then be actuated to drive the rotor 12 into high-speed centrifugal rotation. As one skilled in the art would recognize, one or more of the above rotor mounting components may be made of any suitable metallic or non-metallic material.

[0035] To balance the rotor 12, a diagnostic device may be used to detect imbalances in the rotor 12 and identify at least one target location on the hub 14 and at least one corresponding target weight amount, which can be added to the target location on the hub 14 to assist in properly balancing the rotor 12. Depending on the particular diagnostic device used, a user may input a radius value (e.g., distance from the axis of rotation) indicating that the target location is desired to be on the hub 14 rather than on the rotor body 70. A suitable balance hole 52 corresponding to the target location and a balance weight 16 having a weight relatively close to the target weight amount may then be selected.

[0036] To counteract the imbalance detected by the diagnostic device, at least one selected balance weight 16 may then be threadably engaged with at least one balance hole 52 according to information provided by the diagnostic device. For example, as shown, a single balance weight 16 may be threadably engaged with one of the balance holes 52, while the remaining balance holes 52 may be left unfilled. Alternatively, any number of balance weights 16 may be mounted in any number of balance holes 52 as may be appropriate to achieve the desired balancing of the rotor 12. In either case, the balance weights 16 may be encased within their respective balance holes 52 as described above, and the balanced rotor 12 may be safely spun at high speeds for centrifugation.

[0037] Thereafter, rebalancing of the rotor 12, in addition to detecting any new imbalances in the rotor 12, may be performed, for example, by simply threadingly disengaging one or more balance weights 16 from their respective balance holes 52, relocating the removed balance weights 16 into different balance holes 52, threadingly engaging one or more different balance weights 16 into one or more different balance holes 52, and / or replacing the removed balance weights 16 with one or more balance weights 16 having different lengths and / or masses. The balance weights 16 and balance holes 52 may therefore eliminate the need to repeatedly drill holes in the rotor body 70 or to plug such drilled holes when they are no longer used during rebalancing.

[0038] Although the balance weights 16 and corresponding balance holes 52 have been described with respect to the illustrated hub assembly 10 and rotor 12, the balance weights 16 and balance holes 52 may be incorporated into any suitable hub assembly and / or rotor. For example, the balance weights 16 and balance holes 52 may be incorporated into a hub assembly that does not feature a magnet ring 40 (including magnets 48) and / or annular shield 42. In such cases, a dedicated cover may be used to conceal the balance weights 16, or the balance weights 16 may be exposed. Additionally or alternatively, the balance weights 16 and balance holes 52 may be incorporated into other carbon fiber rotors of various designs and / or rotors constructed of different materials.

[0039] By way of example and not limitation, other exemplary rotors suitable for balancing according to the rotor balancing methods described herein are model F10-4x1000 LEX, F21-8x50y, F12-6x500 LEX, F20-12x50 LEX, F14-14x50cy, F14-6x250y, and F17-6x250 LEX rotors commercially available from commonly assigned Fiberlite Centrifuge, LLC of Santa Clara, CA.

[0040] FIG. 5 illustrates a centrifuge rotor 12a and hub assembly 10a according to an alternative embodiment of the present invention, such as a commonly assigned model F10-4x1000 centrifuge rotor.

[0041] The centrifuge rotor 12a of Figure 5 includes four circumferentially spaced cell hole cavities 80a, each configured to removably receive therein a large-capacity sample container, e.g., a sample container capable of holding at least 750 ml and up to 1000 ml of sample. Exemplary large-capacity sample containers suitable for use with the rotor 12a of Figure 5 are fully described in U.S. Patent Nos. 8,215,508 and 9,987,634, each of which is commonly owned and incorporated herein by reference in its entirety.

[0042] Similar to the embodiment of centrifuge rotor 12 and hub assembly 10 of FIG. 4, the hub assembly 10a for centrifuge rotor 12a of FIG. 5 includes a rotor hub 14a and at least one balance weight 16a removably embeddable within rotor hub 14a, similar to balance weight 16 of FIG. 4.

[0043] The illustrated rotor hub 14a, similar to the rotor hub 14 of FIG. 4, may be constructed of a metallic material, such as titanium, and includes a head 20a and an elongated shaft portion 22a extending axially from the head 20a. The shaft portion 22a includes a threaded outer end surface 24a distal from the head 20a and a threaded outer mid-surface 26a proximal to the head 20a. A central multi-step bore 30a extends through the head 20a and shaft portion 22a of the rotor hub 14a and includes a threaded inner surface 32a located within the shaft portion 22a distal from the head 20a.

[0044] The rotor hub 14a has an annular recess 34a in its bottom side distal from the shaft portion 22a, which opens into a plurality of circumferentially spaced threaded fastener holes (not shown), similar to the fastener holes 36 of FIG. 3A. Each of the fastener holes (not shown) is configured to threadably receive a corresponding fastener (not shown), similar to the fastener 38 of FIG. 3A and FIG. 3B, for attaching the magnet ring 40a and / or the annular shield 42a to the bottom side of the rotor hub 14a. The illustrated magnet ring 40a includes a plurality of through holes (not shown), similar to the through hole 44 of FIG. 3A, each configured to receive a corresponding one of the fasteners (not shown). The magnet ring 40a may also include a plurality of blind holes (not shown), similar to the blind hole 46 of FIG. 3B, in its top side for selectively receiving a plurality of corresponding magnets (not shown), similar to the magnet 48f of FIG. 3A and FIG. 3B. The selected arrangement of magnets on magnet ring 40a results in an identifiable magnetic field via the Hall effect that may be detectable by the centrifuge (or a sensor / reader associated therewith), so that the centrifuge (or a controller associated therewith) can identify the hub 14a and / or rotor 12a, as would be understood by one skilled in the art. For example, the centrifuge (or its controller) may compare the detected magnetic field to various magnetic field values ​​stored in a database to identify the particular rotor 12a or type of rotor 12a within the centrifuge.

[0045] 3A, 3B, and 4, the annular shield 42a includes a plurality of through-holes (not shown), similar to the through-hole 50 of FIG. 3A, each configured to receive a corresponding one of the fasteners (not shown), such that the annular shield 42a can be sandwiched within the recess 34a between the magnet ring 40a and the head 20a of the rotor hub 14a when a fastener (not shown) is threadably received in the corresponding fastener hole (not shown). As described above in connection with the shield 42 of FIGS. 3A, 3B, and 42, the shield 42a can be constructed of a highly magnetic material capable of preventing the magnetic field generated by the magnet (not shown) from being directed upward toward the hub 14a, but rather concentrating the magnetic field downward toward the centrifuge's sensors / readers. In one embodiment, the shield 42a can be constructed of mu-metal (e.g., ASTM A753 Alloy 4).

[0046] The head 20a of the rotor hub 14a further includes a plurality of circumferentially spaced, threaded balance holes 52a that open to the recess 34a. In the embodiment shown, each of the balance holes 52a extends generally parallel to the central hole 30a of the rotor hub 14a. Each of the balance holes 52a is configured to selectively and threadingly receive one of the balance weights 16a for balancing the rotor 12a in a manner similar to the balancing method described in detail above in connection with the centrifuge rotor 12 of FIG. 4.

[0047] Similar to the centrifuge rotor 12 of FIG. 4, the balance weight 16a may be covered by the magnet ring 40a and / or the annular shield 42a, or the balance weight 16a may be concealed within the corresponding balance hole 52a by the magnet ring 40a and / or the annular shield 42a, so that the balance weight 16a is not visible or easily accessible from outside the hub assembly 10a.

[0048] As shown in FIG. 5, rotor 12a includes a rotor body 70a that is symmetrical with respect to an axis of rotation defined by rotor hub 14a, about which a sample contained in a sample container (not shown) positioned within rotor body 70a can be centrifugally rotated.

[0049] The rotor body 70a of FIG. 5 includes a generally cylindrical bore 72a for receiving at least the shaft portion 22a of the hub 14a, the bore 72a being configured to be coaxial with the hub 14a, such that the bore 72a can also define an axis of rotation.

[0050] Extending into the rotor body 70a from the upper cavity 76a are tubular cell hole cavities 80a. Each of the cavities 80a is suitably sized and shaped to receive at least one of the sample vessels therein for centrifugal rotation of the vessels about the axis of rotation. As with the rotor 12 of FIG. 4, it will be appreciated that any suitable number of cell hole cavities 80a may be used. In one embodiment, similar to the rotor 12 of FIG. 4, the rotor body 70a is constructed of carbon fiber material. For example, the rotor body 70a may be compression molded from layers of resin-coated carbon fiber laminate material.

[0051] In the embodiment shown, rotor body 70a and rotor insert 82a are co-molded within bore 72a. Insert 82a includes at least threaded bore 84a for receiving and threadingly engaging threaded outer interface surface 26a of shaft portion 22a of hub 14a to securely mount rotor body 70a on hub 14a.

[0052] With the rotor body 70a resting on the rotor hub 14a, a hub retainer 90a is removably fastened to the hub 14a to further facilitate holding the rotor body 70a, hub 14a, and insert 82a in position relative to one another. The hub retainer 90a includes at least a threaded bore 92a for receiving and threadingly engaging the threaded outer end surface 24a of the shaft portion 22a of the hub 14a.

[0053] The rotor 12a also includes a lid 100a that is removably coupled to the rotor hub 14a over the rotor body 70a, for example, to aid in retaining sample vessels therein during rotation of the rotor body 70a. The lid 100a is generally disk-shaped and includes a central hole 102a and a peripheral groove 104a for receiving an O-ring 106a to provide a fluid-tight seal between the lid 100a and the rotor body 70a when the lid 100a is removably coupled to the rotor body 70a. In one embodiment, the lid 100a is constructed of a carbon fiber material. For example, the lid 100a may be compression molded from layers of resin-coated carbon fiber laminate material.

[0054] Similar to the lid 100 of FIG. 4, the lid 100a can be removably coupled to the rotor body 70a via lid screws 110a. The illustrated lid screws include an upper flange 112a, a threaded lower outer surface 114a, and a multi-step bore 116a. As shown, the threaded lower outer surface 114a is received by and threadingly engages the threaded inner surface 32a of the hub 14a, causing the upper flange 112a to press a spacer 118a against the lid 100a. When the lid 100a is removably coupled to the rotor body 70a via the engagement of the lid screws 110a with the hub 14a and the engagement of the spacer 118a with the lid 100a, it prevents access to sample vessels held in the cavities 80a, such as during high-speed rotation. A tie-down screw or pin 120a can be inserted through the hole 116a in the cap screw 110a and can be threadably coupled to the knob 122a. The tie-down pin 120a can be configured to engage with a cooperating hole in a centrifuge spindle (not shown), which thus assists in attaching the rotor 12a to the centrifuge spindle. As shown, the tie-down pin 120a can be biased away from the centrifuge spindle by a helical spring 124a. A threshold force in the helical spring 124a can be overcome, urging the tie-down pin 120a to engage with the hole in the centrifuge spindle, which can then be actuated to drive the rotor 12a into high-speed centrifugal rotation. As with the centrifuge rotor 12 and hub assembly 10 of FIG. 4, one of ordinary skill in the art will recognize that one or more of the above rotor mounting components can be made of any suitable metallic or non-metallic material.

[0055] While the description of various embodiments illustrates various aspects consistent with the principles of the invention and has described these embodiments in considerable detail, it is not intended that the scope of the invention be limited to such details or to any limitation. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will be readily apparent to those skilled in the art. Therefore, the invention in its broadest aspects is not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope of the general inventive concept.

Claims

[Claim 1] 1. A centrifuge rotor comprising: a rotor body having a plurality of tubular cavities each configured to receive a sample vessel therein; a rotor hub assembly for the centrifuge rotor; a rotor hub configured to transmit torque from a centrifuge spindle to the rotor body; The rotor hub assembly includes: a rotor hub including a head, an elongated shaft portion extending axially away from the head, and a central bore extending through the head and the shaft portion; a ring fastened to the head, The centrifuge rotor, wherein the head includes a plurality of balance holes each configured to selectively receive at least one balance weight, and the ring encases the balance weights.

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